Closing All Shared Files on the Network [duplicate]
Solution 1:
The command you are using is not a native PowerShell command. However, PowerShell does come with a lot of functions to control SMB connections and shares.
What you are looking for could be this:
Get-SMBOpenFile | Close-SMBOpenFile -Force
This will close all files opened via file shares. You can also manage SMB Connections (Get-SMBConnection) and other things. With Get-Command *smb* you will get a list of all SMB related commands.